As one example of a semiconductor device having a power supply circuit, there is a DC-DC converter. For example, Published Japanese Translation of a PCT Application No. 2003-528449 (Patent Document 1) discloses a multi-chip module (hereinafter, referred to as MCM) which includes a MOSFET (metal oxide semiconductor field-effect transistor) gate driver, two power MOSFETs, and a relevant passive element including an input condenser, all of which are installed on a ball grid array substrate, and is packaged in a single chip.
Further, for example, Japanese Patent Application Laid-Open Publication No. 2004-342735 (Patent Document 2) discloses a semiconductor device provided with a power MOS-FET for a high-side switch, a power MOS-FET for a low-side switch, and a driver IC driving the power MOS-FET corresponding to power IC used for a non-isolated DC-DC converter in one package.
Further, for example, Japanese Patent Application Laid-Open Publication No. 2005-217072 (Patent Document 3) discloses an MCM in which a controlling power MOSFET chip, a synchronizing power MOSFET chip electrically connected to the controlling power MOSFET chip in series by a plate-shaped conductor member, and a driver IC chip turning on and off an operation of the chips are sealed in a sealing material.